


Lend a Hand

by larkscape



Category: Voltron: Legendary Defender
Genre: Getting Together, Guilt, M/M, Pining, Porn with Feelings, Sex with a Disembodied Limb, Sexsomnia, Sleepwalking
Language: English
Status: Completed
Published: 2018-12-30
Updated: 2018-12-30
Packaged: 2019-09-30 07:41:49
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,508
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17219762
Author URL: https://archiveofourown.org/users/larkscape/pseuds/larkscape
Summary: Shiro's new floating arm sleepwalks — straight into Keith's bed and under his clothes.Keith doesn't protest as much as he knows he should. Shiro would never touch him like this while awake, but Keith will take whatever he can get.





	Lend a Hand

**Author's Note:**

> /emerges from the brutal hellscape of the holiday season to bring you more smut
> 
> Written for FFA's Post 1000 Prompt & Fill Fest, for this delightful prompt: [Sheith, arm sexsomnia](https://fail-fandomanon.dreamwidth.org/344797.html?thread=2002294749#cmt2002294749)

 

The blankets shift, oddly heavy, as Keith wakes. Ugh, what time is it? It’s dark in his room on the Atlas and there’s no noise he can hear beyond the background hum of the engines. He wonders what woke him. He doesn’t have the jittery feeling he gets from a nightmare; he just feels groggy.

The blankets shift again.

“Go back to sleep,” he grumbles at Kosmo, and gets a sleepy huff in his hair for the trouble.

Something grips his waist. Something that is definitely not his wolf. Keith scrambles to lift the blankets, heart drumming behind his ribs, to find—

Shiro’s arm?

Lying in the sheets, right in the center of the curled shape Keith’s body had made, is Shiro’s prosthetic arm. Thick fingers, broad palm, and long forearm, made of white and silver alloys with a blue glow at the elbow end. Nothing else it could be. As Keith watches, shocked motionless, it slides closer to him, the fingers bumping his hip and climbing under his sleep shirt to curl around his side again. The thumb strokes up and down his abs lazily, right next to his navel.

“Shiro?” Keith asks blankly. The arm doesn’t respond except to drape more heavily across his waist. The fingers squeeze gently and loosen again.

“What… the hell…? Shiro?”

 

The arm doesn’t seem to want to let go, so Keith cradles it to his waist as he stalks through the Atlas’ darkened hallway toward the captain’s quarters. He doesn’t have to go far; Shiro put the paladins in rooms just down from his own. Hopefully no one will see him wandering around in the middle of the night with Shiro’s disembodied hand. Hopefully no one will notice that those fingers are still stroking over his stomach, or that he’s halfway to hard in his boxers because of it.

Keith _likes_ this hand. He’s not sure how he feels about it seeking him out at night when its owner has never done the same.

When Keith reaches the end of the hall, he finds Shiro’s door unlocked. He presses the scanner, ready to stomp inside and demand an explanation, but stops short when he gets a good look. Shiro is facedown on the mattress with all the blankets bunched over his hips, fast asleep. His broad, scarred shoulders are bared by the tank top he wears to bed, and the skin catches the light filtering in from the hallway. Keith’s mouth goes dry.

Oh god. Shiro’s arm was sleepwalking. Shiro’s arm activated itself, unlocked the door, and wandered all the way into Keith’s bed, and Shiro has _no idea._

Keith pulls at the arm again. This time, maybe because it’s near Shiro, it finally lets go. Carefully, Keith settles it on the bed next to Shiro’s sleeping form, then walks backward toward the door. Shiro never stirs.

 

Keith is only just lifting his own blankets to climb back into bed when he feels that touch on his waist again. Kosmo makes an inquisitive, sleepy noise as Keith forces air noisily out through his nose and climbs back out of bed to return the wayward limb to its rightful home. He makes absolutely sure to lock the door as he leaves this time.

The peace lasts long enough for Keith to get in bed again and fall back asleep.

 

When he wakes next, it’s from a _very_ nice dream, and it takes him long seconds to realize that the hand he feels on his cock is real and not just a vivid memory. But no, that is definitely not his own hand.

It’s Shiro’s. Fuck, no wonder he couldn’t tell it from the dream.

Those thick fingers — broad, big, why did they make it so _big?_ — get under his boxers and wrap around his cock, stroking it slowly from root to tip. Keith sucks a breath through his teeth and tries not to moan out loud, but he can’t help the way his hips buck into the pressure.

He shouldn’t— shouldn’t be doing this.

_“Shiro.”_

He doesn’t stop, though.

When Shiro’s fingers start to explore, Keith lets it happen. He lets Shiro’s hand fondle his balls with an endearing sort of sleepy clumsiness, lets it squeeze around his cock again and jerk him off as he shoves his face in the pillow to muffle the noises he makes, the helpless cries of Shiro’s name. Lets it coax his orgasm out of him, then lets it milk him for too long afterward, until he’s so overstimulated that tears leak from his eyes. He has to physically unwrap each finger and hug the whole arm to his chest to keep it from dragging his cock right back into hardness again.

It’s too much to ask Keith not to kiss those fingers after, not when they’re right under his lips, not when they just wrecked him like that. The hand cups his cheek, stroking his cheekbone, and gradually goes limp.

Keith lays awake for a long while.

Eventually, he checks the time. It’s about an hour before Shiro usually wakes.

“Hey,” he says, nudging Kosmo with his elbow. God, he did all that with his wolf in the bed. He’s a bad dog owner.

Kosmo makes an unimpressed noise and turns his back.

“I know, look, I’m sorry. But can you take Shiro’s arm back to him? He’s going to miss it soon.”

With a look of deep disapproval for Keith’s disrespect for sleep time, the wolf does as asked.

Shiro arrives at breakfast later that morning none the wiser. Keith watches the fingers of Shiro’s prosthetic arm flex around a fork and feels blood rush to his face. He can’t bring himself to make eye contact. When he mumbles an excuse about training and darts from the room with his breakfast only half-finished, Shiro lets him go without a word.

 

The arm is back that night, draped across Keith’s waist like Shiro is spooning him, and Keith doesn’t have the willpower to remove it this time. He lays his own arm over the top and laces their fingers together.

“This is a bad idea,” he tells it, or himself, or maybe Kosmo. None of them respond. He lets the arm stay.

 

He wakes later in the night, not unexpectedly, to feel Shiro’s hand clenched low on his hip. Fingers wrap tight around his iliac crest, but they’re so long, so big, that they reach from the base of his cock all the way around, with the thumb touching his spine. The arm tugs on him with small, rhythmic movements, pulling his hips back and down, and— oh god, down at the end of the hall in his own bed, Shiro’s dreaming about fucking. The hand is pulling his hips back to meet Shiro’s, rocking him onto Shiro’s cock.

Is Shiro dreaming about fucking Keith? He can only hope.

Keith shoves two fingers in his mouth and then gets them between his legs as fast as he possibly fucking can. He wants— no, he can’t think about it; that way lies madness. He just wants something in his ass while Shiro’s sleepwalking prosthetic arm keeps rocking him into phantom thrusts from a body that _isn't here._

The spit is only barely enough, but Keith doesn’t care. He shoves both fingers inside at once. It stings but it’s a good sting. It reminds him that this isn't real. Shiro would never make it hurt like—

But wouldn’t he? It’s not like Keith would know. It’s not like Keith could _ever_ know; it’s not like Shiro would be interested in the first place.

No, Shiro’s hand is here, it’s here and it’s _good,_ even through the guilt twisting in his gut, and Keith doesn’t want to think about anything but how incredible it would feel to be held in both of Shiro’s big hands and yanked down onto his cock. The fingers in his ass will just have to do for the fantasy. He shoves them deeper, curves them until he finds his prostate, and rubs it mercilessly while Shiro’s fingers clench on his hip.

If this is what he can have, he’ll take it.

He gets his other hand around his cock, and when he comes, Shiro’s name is on his lips again. The first spurt hits his chin.

 

There’s another round near 0400. Shiro’s hand skims up his chest under his shirt to rub his nipples for long, torturous minutes, drawing Keith up from sleep already writhing. Then the hand wanders back down and tugs at his cock, too slow, too loose, until Keith is whining continuously into the pillow and humping the metal fist.

Then the grip goes lax. Shiro’s slipped into deeper sleep again.

Keith almost cries with frustration as he finishes himself off. He leaves his come all over Shiro’s fingers in some sort of obscure punishment that doesn’t even make sense to him, but he’s still careful to ask Kosmo to put the arm back before Shiro wakes.

 

Shit, Keith has no idea what he’s doing. He avoids Shiro all day long.

 

“Keith?” Shiro asks that evening, when he’s managed to corner Keith outside the mess hall right before dinner.

Keith forces his gaze up. Shiro’s eyes are so bright. “Yeah?” Keith replies, and it feels too breathy in his mouth, but Shiro doesn’t mention it.

“...Is everything all right? You know you can talk to me, right?”

No, oh no, he’s been making Shiro _worry,_ he never meant to— “Sorry, Shiro. Yeah, everything’s fine. I’ve, uh, been a little off today, haven’t I?”

“A little,” Shiro says, raising an eyebrow.

“Really, I’m fine.” He gropes for an excuse that isn’t a flat-out lie. “I just had a strange dream, and it left me… on edge, I guess.”

Inexplicably, Shiro colors. “Oh,” he says, glancing down. “Okay, yeah. That’s— okay. I get it.” Then he looks up again, with fresh determination. “Do you… want to join me for dinner? I talked Hunk into making grilled cheese sandwiches. We have real cheddar onboard right now.”

Shiro's earnest expression is just too much. He looks so hopeful. Keith starts to nod, but then thinks about actually sitting down at one of the long tables with Shiro, watching him eat, knowing exactly what those fingers did last night and what they're probably going to do again tonight and knowing that Shiro doesn't have a clue, that Shiro has never even considered—

Keith can't do it.

“Maybe next time,” he says, strangled, and darts away. He doesn't look back. He doesn’t want to see Shiro’s disappointed face.

 

The arm is back again.

Keith is going to lose his mind at this rate.

Ignoring the burn of guilt is getting easier with practice. He’s started sleeping naked. He lays on his side, letting the hand curve around his shoulder and knead, and if he holds on to it too tightly, well, Shiro isn't awake and sleeping people aren't entitled to opinions on the subject.

He wishes the rest of Shiro were here. He wishes he were brave enough to insert himself into Shiro’s bed, instead of… _this,_ whatever it is. Shiro’s sleepwalking arm finding any warm bed to crawl in and Keith being too stupid to turn it away. He twists his face into the side of Shiro’s hand, letting his lips drag across the smooth surface.

The thumb curves to stroke his chin. He licks it. It presses softly on his lower lip.

This is the first time Keith has instigated; before, the hand was already working him over when Keith woke up, but there’s only so much temptation he can resist, and Shiro’s thick thumb right in front of his mouth is not something he can withstand.

With a helpless noise, he opens his mouth.

To his surprise, the thumb doesn’t immediately dive inside. Instead, it traces over his lower lip again, and then the whole hand turns as two fingers push in instead, stroking over his tongue. Keith closes his mouth around them, licks between them and across the knuckles, then sucks a little. The fingers shove deeper. God, they’re so _big._ It is completely unfair how large they made this hand.

Keith whimpers when the fingers withdraw. But then they trace down his neck, then lower, slipping wetly along his sternum, and Keith suddenly doesn’t mind their absence from between his lips. Every touch, every minor brush against his skin, sets his blood surging. Thick fingertips trip over his abs, circle his navel, follow the thin trail of hair down to the base of his hard cock — and sidestep it completely.

“Shiro,” Keith whines through his teeth, shifting his hips restlessly.

But the fingers just nudge the inside of his thigh until he lifts it, spreads himself open for Shiro’s touch, and then the hand moves down and around to spread his ass cheeks. One thick finger probes intently at the crease between, finding his hole and pressing too hard. Keith sucks in a startled breath.

It’s so easy to forget that this isn’t actually Shiro, but then the hand does something like this, trying to get inside him with no more lube than half-dry spit, and Keith is forcibly reminded that he’s fucking a _sleepwalking prosthetic._

What the hell is he doing?

He’s not going to stop, though. God, Shiro’s probably dreaming about fingerfucking someone else entirely, but Keith can’t help himself. Not when that hand, that gorgeous, huge hand, is right there on his ass and begging for entrance. He stretches toward the bedside table, and the hand grabs onto one cheek, fingers digging in uncomfortably. If Keith didn’t know better, he’d say it was almost frantic.

“Yeah, yeah, calm down,” Keith tells it. “I'm just getting lube. You're not sticking those monster fingers in me without it.”

When he’s retrieved the bottle, he strokes the fingers until they relax their grip. Then he slathers them in lube, and they get right back with the program.

The first one pressing inside is almost enough to make Keith white out. He muffles his moan in the pillow, twisting up on his knees with his ass in the air, while one thick finger does the work of two and makes a valiant effort at turning his brain inside out. Keith keeps making helpless, needy noises, his hips hitching back on the hand, begging wordlessly for more.

A second finger nudges at his hole. Keith grabs his cock in a stranglehold and shoves his ass back, demanding, forcing the tip inside. The stretch is incredible.

Then his brain really does turn inside out. _Fuck,_ Shiro’s fingers are unbelievable, warm and thick and unyielding as they drive inside him again and again, curving just right. He can’t stop moving, writhing on Shiro’s hand, jerking his cock with his face smashed in the pillow. He can’t even tell if he’s still making noise. He thinks he might be begging, repeating Shiro’s name, pleading for more, harder, _faster,_ but he can’t help it. Fuck, he’s _so close—_

The hand shudders and goes still.

“What…” Keith groans muzzily. The hand isn’t limp, like it sometimes goes; it’s just _still,_ holding rigidly in place. Keith tries to catch it around the wrist and move it himself, but the position is all wrong and he can’t get a solid grip.

“No no no, dammit, don't _stop,_ god,” he whines, shoving his hips back. That gets him a little more motion, but Shiro’s fingers aren’t in the same shape anymore and Keith’s too far gone to be able to find the right angle on his own. “Fuck. _Shiro._ I should have known you'd be like this, you fucking tease, of all times to fall back asleep, fuck, everyone thinks you're this perfect captain but you're just an asshole, fuck, _fuck,_ right when I was— _now?_ Fuck you, Shiro, come _on—”_

“…Keith?”

Keith freezes.

Shiro is in his doorway. The real Shiro. Awake Shiro. His eyes are wide and his hair is all mussed from bed and he’s staring at Keith.

At Keith’s ass, thrust up in the air, and his own hand buried in it.

Keith drops flat on the mattress and tries to suffocate himself in the blankets, twisting around in a doomed effort to cover himself. Shiro’s already seen everything anyway.

The hand goes with him.

“Oh god,” Keith whispers. “I’m— god, I’m sorry, Shiro, I— _fuck._ I don’t know what to say. I’m sorry.”

The silence stretches. Keith can’t bring himself to look up; he scrunches his hands in the blankets, tries to pull them closer around his face. Shiro’s fingers are still inside him, unmoving.

“...So this is where it went.” Shiro’s voice is even. He sounds completely ordinary, like he’s discussing the charging status of the MFE ships instead of walking into his best friend’s room in the middle of the night to find his own disembodied hand in Keith’s ass.

Against his better judgement, Keith whispers, “What?”

“My arm.” Shiro’s bare feet make quiet sounds on the carpet as he draws closer. “I woke up because Kosmo showed up in my room, and…”

Keith swallows past his dry throat. “You knew?” he makes himself ask. “About the arm?”

“Well, I didn't know it was coming _here,_ but I knew it was wandering. I should have guessed it would go to you.” Shiro’s at the edge of the bed now; Keith can tell because the mattress dips. Shiro must have sat down. “Keith. Keith, look at me.”

Keith shakes his head, just once. He _can’t._ He feels so, so guilty. It coils inside him, under his ribs.

“Please.” Now there’s emotion bleeding into Shiro’s voice, but Keith can’t place it. He turns enough to free one eye from the blanket cocoon and raises its gaze over his shoulder to Shiro’s face.

“I’m sorry,” Shiro says. “I didn’t mean for this to happen.”

 _“You_ didn’t mean— _I’m_ the one who—”

Shiro is smiling at him.

Keith falters, and stares. He has no idea what’s going on.

“I knew it was a risk,” Shiro continues, shifting so his body brackets Keith’s on the mattress, “putting your room so close to mine. I’m sorry my arm sought out what I wouldn’t allow myself. But, Keith?”

“...Yeah?” His heart is pounding in his throat. Does Shiro really mean…?

“I may be a tease,” Shiro says, chuckling softly, pink-cheeked, leaning over him, “but I always follow through.”

“Shiro—?” Keith breaks off on a whine as the fingers inside him start to move again.

“Okay?” Shiro asks in a whisper.

“God, yes,” Keith replies immediately, vehement. “Yes. Oh, _fuck— yes, Shiro—!”_

And then Shiro leans even closer, and his mouth is right there in front of Keith’s, and there’s no way for Keith to deny how much he needs to kiss him so he doesn’t even try, just lunges up and mashes their lips together. Something warm unfurls in his chest at the contact.

Shiro makes a pleased noise and deepens the kiss. His fingers flutter over just the right spot, and in a blink, Keith’s right at the edge again. Shiro’s _here,_ in Keith’s bed, his huge fingers are still working inside Keith, and his mouth tastes _so good._ There’s no way Keith could last much longer, not in any reality.

“Shiro,” he whines, squeezing his eyes shut, rutting against the blankets still wrapped halfway around him.

“Come on, Keith,” Shiro says warmly, his other arm curving around Keith’s shoulders and pulling him close. “I want to actually see it this time. God, you feel so good. I’ve been going _crazy._ I keep having these dreams about you—”

“Did you— _ah—_ dream about fucking me last night?”

Shiro hisses in his ear. _“Yes.”_

“Good, ‘cause your hand was— _fuck,_ was with me, right here—” Keith drags Shiro’s hand from his shoulder to his hip, tries to make him replicate the grip from the wrong side with lust-clumsy limbs while those thick metal fingers thrust ceaselessly inside him. “And you were— pulling, like— yeah, like that, and I had my fingers in my ass, wishing it was you— oh, _ah, Shiro—!”_

“God, fuck, _Keith—”_

Shiro’s flesh hand digs under the blankets to wrap around Keith’s cock at the same moment that the metal one in his ass presses relentlessly against his prostate, and Keith’s orgasm sucks all the air out of his body. He arches, clutching fistfuls of Shiro’s shirt, and comes all over his hand.

Shiro works him through it, slowing gradually, peppering his throat with kisses until Keith’s spine relaxes and he can bring his chin down. Then Shiro kisses his lips instead.

With one more lingering kiss, Shiro pulls back and cups Keith’s cheek in his flesh hand — which still has come on it, not that Keith particularly cares. Shiro traces his thumb over the scar on Keith’s cheek and a soft, regretful look passes over his face. “I love you, too, you know. Wish I’d said it sooner.”

“Yeah, well,” Keith says, catching that hand and kissing it. “Your arm has more brains than you do.”

 


End file.
